The present invention relates to a semiconductor device, and relates to, for example, a semiconductor device which assists a supply of power generated by a power source to a functional circuit.
A semiconductor device is provided with a smoothing capacitor between a power supply terminal and a ground terminal outside the semiconductor device to suppress a fluctuation of a power supply voltage. It is demanded that a power circuit which supplies power to the semiconductor device has capability to supply power including charges to be charged to this smoothing capacitor upon activation of the semiconductor device. Hence, upon activation of the semiconductor device, more power than that in a normal operation state is temporarily demanded. Hence, a technique of supplying power to a load circuit while charging a smoothing capacitor is disclosed in Japanese Unexamined Patent Application Publication No. 2001-273043.
In a power circuit disclosed in Japanese Unexamined Patent Application Publication No. 2001-273043, a smoothing capacitor converts the voltage obtained from a rectifier circuit into a direct current voltage, and a regulator IC stabilizes the direct current voltage. Further, a current bypass resistor is provided in parallel to the regulator IC.